The Science Odyssey Web site currently contains many accessibility features, and more are being added. The site is designed to make navigation as simple as possible for all users, especially those using screen readers. All graphic links, such as image maps, are accompanied by text equivalents. All images make use of alt-text tags. (To learn more about alt-text tags, see Instructions for Blind and Visually Impaired Users.) Interactive games, which make use of Shockwave, are accompanied by text descriptions or text versions of the activity.

Level 2 pages contain activities, games or information relating to a particular category. Where necessary, some Level 2 pages contain text-only versions to make navigation easier when using a screen reader. General site navigational links may be found at the bottom of each page.

Alt-text Tags
All images on this site are accompanied by brief alt-text tags. These tags are visible only if you turn off the image-loading function of your browser. To disable this function, choose the appropriate browser below and follow the instructions.

Netscape Navigator 3.0 (Macintosh)
From the Options menu, select Auto Load Images. This will toggle the image-loading feature off. (Note: if you do not see a check mark next to Auto Load Images, this feature is already turned off.) Open the Options menu again and choose Network Preferences.... Select the Cache flip card and click on the Clear Disk Cache Now button. Click OK in the dialog box. This will empty your cache of all previously loaded images. Click OK again to return to the browser. Quit Netscape and restart.

Netscape Navigator 3.0 (PC)
From the Options menu, select Auto Load Images. This will toggle the image-loading feature off. (Note: if you do not see a check mark next to Auto Load Images, this feature is already turned off.) Open the Options menu again and choose Network Preferences.... Select the Cache flip card and click on the Clear Disk Cache Now button. Click OK in the dialog box. This will empty your cache of all previously loaded images. Click OK again to return to the browser. Quit Netscape and restart the application.

Alternatively, from the keyboard you can press Alt+O, A to toggle the image-loading feature off. To clear the cache, press Alt+O, N, Alt+Y, Enter, Enter. Quit Netscape and restart the application.

Netscape Communicator 4.0 (PC)
From the Edit menu, choose Preferences. In the Category window, click on Advanced. Click on the checkbox next to Automatically Load Images to deselect this item. Next, in the Category window, click on the plus sign next to Advanced to reveal the subcategories. (If you see a minus sign, the subcategories are already visible.) Click on Cache. Click the Clear Memory Cache button. Click OK in the dialog box. This will empty your cache of all previously loaded images. Click OK again to return to the browser. Quit Netscape and restart.

Alternatively, from the keyboard you can press Alt+E, E to open the Preferences dialog box. Use the Tab key to move into the Categories window. Press the down arrow to move the focus to Advanced, then press Alt+I to deselect the image-loading feature. Press Enter to close the Preferences box.

To clear the cache, press press Alt+E, E to open the Preferences dialog box. Use the Tab key to move into the Categories window. Press the down arrow to move the focus to Advanced, press the right arrow to display the subcategories (if they aren't already displayed), then press the down arrow to move to Cache. Press Alt+Y, Enter, Enter. Quit Netscape and restart.

Internet Explorer 3.0 (Macintosh)
From the Edit menu, choose Preferences.... Click on the triangle next to Web Browser to reveal the subcategories, then click on Web Content. (If the triangle is already pointed downwards, the subcategories are already visible.) Click on the checkbox next to Show Pictures to deselect this item. Next, in the Web Browser list, click on Advanced. Under Cache, click on the Empty Now button. Click the OK button to close the Preferences box.

Internet Explorer 3.0 (PC)
From the View menu, choose Options.... Select the General flip card and click on the checkbox next to Show Pictures to deselect this item. Click OK to close the dialog box.

Alternatively, from the keyboard you can press Alt+V, O to open the Options dialog box. Use Ctrl+Tab to choose the General flip card, the press P to deselect the Show Pictures checkbox. Press Enter to close the dialog box.

D-links
Most images are followed by a D hyperlink, or D-link (in some cases, the D precedes the image). Selecting this D-link will bring you to a textual description of the image. The description is typically two or three sentences long. At the end of the description is a Return link, which will take you back to the original image.

Colors
If the color schemes used in this Web site pose problems, you may override them with your own choices. To do so, choose the appropriate browser below and follow the instructions.

Netscape Navigator 3.0 (Macintosh)
From the Options menu, choose General Preferences.... Select the Colors flip card. In the Color Control window, click on Always Use Mine. In the Use My Colors For window, click on the features you want to customize (links, followed links and text). To customize the colors, click on the color box next to each feature. Select a color by moving the slider on the color bar to the desired shade of lightness, then select the appropriate color from the color wheel. Click OK when finished. In the Background window, click on Custom. To customize the background color, click on the color box and select a color as outlined above. When you're finished, click on the Apply button, then the OK button.

Netscape Navigator 3.0 (PC)
From the Options menu, choose General Preferences.... Select the Colors flip card (if it is not already selected) and click on the checkbox next to Always Use My Colors. Then click on the checkboxes next to the features you want to customize: Links, Followed Links and Text. To customize the colors, click on the Choose Color... buttons for each of these items. To change the background color, click on the Custom checkbox and then the Choose Color... button. When finished, click the OK button.

Alternatively, from the keyboard you can press Alt+O, G to open the General Preferences... dialog box. Use Ctrl+Tab to select the Colors flip card (if it is not already selected). Press the first letter of the feature you want to customize (Links, Followed Links, Text; press C for Background) and then press the Tab key to move to the Choose Color... button for each particular item. Finally, use the Tab key to move the focus to Always Use My Colors; press the spacebar to select this feature. Press Enter when finished.

Netscape Communicator 4.0 (PC)
From the Edit menu, choose Preferences... to reveal the main dialog box. In the Category window, click on the plus sign next to Appearance to reveal the subcategories. (If you see a minus sign, the subcategories are already visible.) Click on Colors. In the Colors window, click on the Text color button to reveal the color palette. Select the color you want to use for text and then click OK. Next, click on the Background color button, select the color you want to use for background display and then click OK. Click on Use Windows Colors to deselect that item, then click on Always Use My Colors to select that item. Finally, click the OK button.

Alternatively, from the keyboard you can press Alt+E, E to open the Preferences... dialog box. Use the Tab and up or down arrow keys to move the focus to Appearance. Press the right arrow key to reveal the subcategories (if they aren't already displayed) and the press the down arrow to move the focus to Colors. Press Alt+T and the spacebar to reveal the Text color palette. Select the color you want to use for text display, then press the Enter key. Press Alt+B and the spacebar to reveal the Background color palette. Select the color you want to use for background display, then press the Enter key. Press Alt+W to deselect Use Windows Colors; press Alt+A to select Always Use My Colors. Press the Enter key when finished.

Internet Explorer 3.0 (Macintosh)
From the Edit menu, choose Preferences.... Click on the triangle next to Web Browser to reveal the subcategories, then click on Web Content. (If the triangle is already pointed downwards, the subcategories are already visible.) Click on Allow Page to Specify Colors to deselect this item. In the Web Browser list, click on Browser Display. Click on the color boxes next to Text and Background to change the colors for these features. Select a color by moving the slider on the color bar to the desired shade of lightness, then select the appropriate color from the color wheel. Click OK when finished. When finished, click the OK button.

Internet Explorer 3.0 (PC)
From the View menu, choose Options.... Select the General flip card. In the Colors window, click on Use Windows Colors to deselect that item. Click on the Text color button to reveal the color palette. Select the color you want to use for text and then click OK. Next, click on the Background color button, select the color you want to use for background display and then click OK. Click the OK button when finished. Note: some pages use predetermined colors which override your choices in Internet Explorer 3.0.

Alternatively, from the keyboard you can press Alt+V, O to open the Options... dialog box. Press Ctrl+Tab to select the General flip card. Press Alt+W to deselect Use Windows Colors. Press Alt+T and the spacebar to reveal the Text color palette. Select the color you want to use for text display, then press the Enter key. Press Alt+B and the spacebar to reveal the Background color palette. Select the color you want to use for background display, then press the Enter key. Press the Enter key when finished. Note: some pages use predetermined colors which override your choices in Internet Explorer 3.0.